1. Field of the Invention
The present invention relates to a brake device and a saddle riding type vehicle, and more specifically to a brake device in which a front wheel brake and a rear wheel brake are activated in association with each other by one brake operator, and a saddle riding type vehicle including the brake device.
2. Description of the Related Art
A motorcycle is known as a kind of saddle riding type vehicle. The motorcycle is provided with brakes to brake the rotation of a front wheel and a rear wheel. Motorcycles with an interlocking brake device have already been put to practical use. The interlocking brake device allows brakes for front and rear wheels of a motorcycle to be operated by one lever.
In an interlocking brake device disclosed in Japanese Patent No. 4526135, a braking force distribution characteristic curve is changed based on traveling information such as vehicle speed and wheel slipping states. The braking force of the front wheel brake and the braking force of the rear wheel brake are controlled based on the braking force distribution characteristic curve.
The interlocking brake device disclosed in Japanese Patent No. 3329851 allows a rider to adjust the ratio of the braking force of the front wheel brake and the braking force of the rear wheel brake as the rider desires among ideal braking force distribution characteristic curves for riding single and riding double.
In the brake device disclosed in JP-A 2005-535513, the ratio of the braking force of the front wheel brake and the braking force of the rear wheel brake is changed depending on a reduction ratio to a ratio based on an ideal braking force distribution characteristic curve or a predetermined ratio in order to maintain safety and operation comfort.
The above-described prior art documents disclose how to set a ratio of the braking force of the front wheel brake and the braking force of the rear wheel brake by changing the braking force distribution characteristic curve depending on slipping states, vehicle speed, and the like and how a rider can adjust the ratio of the braking force of the front wheel brake and the braking force of the rear wheel brake.
FIG. 11 shows a state of motorcycle leaning at a lean angle θ. A motorcycle sometimes turns as its vehicle body is leaning as shown in FIG. 11. When the motorcycle turns while its vehicle body is leaning and the front wheel brake acts hard, a phenomenon occurs in which the vehicle body rises. More specifically, the lean angle θ is reduced. It is therefore difficult for the motorcycle to turn while its vehicle body is leaning and the brake device is activated. However, it is generally easier for the motorcycle to turn when the vehicle body is leaning and the speed is lower.